Synthetic polymer textile filament



June 7, 1960 M. c. HOLLAND 2,939,202

SYNTHETIC POLYMER TEXTILE FILAMENT Filed Dec. 31, 1959 2 Sheets-Sheet 1 I I o I o o o o o o o g E g g 8 8 Q saaasao v INVENTOR MARLIN C. HOLLAND ATTORNEY FIG?) June 7, 1960 M. c. HOLLAND 2,9 9,

SYNTHETIC POLYMER TEXTILE FILAMENT Filed Dec. 31, 1959 2 Sheets-Sheet 2 INVENTOR MARLIN C. HOLLAND ATTORNEY United States Patent l SYNTHETIC POLYMER TEXTILE FILAMENT Marlin C. Holland, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Dec. 31, 1959, Ser. No. 863,189

8 Claims. (Cl. zs-sz This invention relates to novel synthetic fibers and filaments having a unique combination of improved optical and physical properties.

Fibers having various cross-sectional shapes have been prepared to provide textile materials having certain desirable properties. For example, fibers having a Y- shape cross section have been used in fabrics to provide bulk. Similarly, fibers have been made with other cross sections, e.g., ribbon, dumbbell or dogbone shape and cruciform, to provide improvements in other textile properties. Fibers having a trilobal configuration which provide unique luster highlight in addition to other desirable properties are described in my copending application Serial No. 822,514, filed June 24, 1959, which is a continuation in-part of my application Serial No. 748,447, filed July 14, 1958, now abandoned. The filaments described in my copending application have three symmetrical lobes, with each lobe having essentially straight side portions extending outwardly and tangent to an arcuate portion at each end. I have now discovered that this unique luster highlight is also found in other trilobal filaments having side portions which are convex. In addition to the unique optical properties, the fibers having convex side portions provide other improved properties which are particularly desirable in flat textile fabrics.

Accordingly, it is an object of this invention to provide fibers and filaments having a trilobal cross section which are particularly adapted for use in flat textile fabrics. A more specific object of this invention is to provide novel synthetic fibers and filaments which, when incorporated in apparel fabrics, exhibit a unique combination of luster highlight, drapability, resistance to soiling, covering power, and wrinkle resistance. Other objects will appear hereinafter.

The objects of this invention are accomplished by providing novel filaments and fibers prepared from synthetic polymers having a cross-sectional shape consisting of three convex sides and three arcuate terminal portions. The convex sides may be made up of two straight portions which join the curved portion to the adjacent arcuate tips. The tips of the three terminal portions of the cross section of the filaments define a circle having its center equidistant from the tips. The cross section may be divided into three porfions, each including a tip, which are essentially symmetrical in shape. Filaments of the present invention are members of the tribrachiate family and may be defined by any three of mentioned are obtained.

Throughout the specification and claims, the terms filaments and fibers will be used interchangeably in their usual and accepted meaning. By the term luster 2,939,202 Patented June 7, 1960 2 highlight is meant the frequency and the degree of-concentration (in area) or the high intensity light reflected from a small area of a yarn or textile material relative to the average of the total amount of light reflected from a portion of the same yarn or textile material which includes the small area. By the term soiling resistance is meant the apparent resistance of a textile materialto visible soil which may be independent of the soiling which may actually occur.

The present invention will be more fully understood by reference to the following detailed description and the accompanying drawings in which:

Figures land 2 are enlarged representations of cross sections of the filaments of this invention;

Figures 3 and 4 are graphs showing the area in which the parameters defining the crosssection of the filaments of this invention appear; and

Figure 5 'is an enlarged view of a spinneret'orificewhich may be used in spinning the filaments of the present invention.

Referring now to Figs. 1 and 2, the cross-sectional shapes of the filaments of this invention are defined by the following parameters:

(1) The ratio of the tip radius r to the radius -R of a circle a havinga center 0 circumscribed about the tips b;

(2) The arm angle A formed by extending 'a line tangent to both the convex side a and the are generated by the tip radius r, (when there is a straight portion joining the tip and convex side, this straight portion will be a common tangent to both the tip circle andt-he convex side and will determine the angle A. When there isno straight portion, the convexv side and the tip circle .will have a common tangent which will determine the angle A); and g V (3) The ratio of'the radius R to the radius R of a circle having center 0 inscribed within the cross section which will be referred to as the modification ratio M.

As previously indicated, the equations set forth in my copending application express the interrelation of the aforementioned parameters. In all of the filaments of the present invention, the arm angle A is greater than 60. In general, the modification ratio M is from about 1.1 to about 1.63, the tip radius ratio is from about zero to about 0.71, and the arm angle A is from about 70 to 150. However, not all combinations of the aforementioned parameters will provide filaments having the improved properties heretofore described. It is only filaments having combinations of parameters selected from the cross-hatched areas of Figs. 3 and 4 which provide the new and unusual properties. It will be noted that the areas shown on the graphs are not regular geometrical figures as one might expect. If a three-dimensional plot were made incorporating the points on the graphs, it would appear as a volume with those filaments exhibiting maximum luster being found at the position where angle A is about is about 0.3, and M is about 1.28.

It is indeed surprising that the filaments of the present invention exhibit a unique luster highlight since sparkle and glitter have heretofore been thought to be attributable to the presence of relatively large, fiat surface areas along the fiber axis. It is also surprising that the filaments of the present invention exhibit a much higher resistance to wrinkling and soiling than fibers having either a triangular at C. The

or Y-shape cross section while at the same time exhibiting the luster highlight property.

In preparing the filaments of the present invention, a

spinneret'having orificesof a configuration similarto that :parameters'may'occur along'thelength of the filament or from filament-.to-filament in a bundle without adversesections may not be perfectly symmetrical. Y a

The denier of the filaments may vary within wide limits.

Deniers in the range'from 1 to '35 are usually preferred;

however, deniers of250 or highermay'be utilized, de-

pending on the end use of the textile material being prepar d V l i This invention will be more fully described inthe following examples which are illustrative and in which parts and percentages are by weight unless otherwise specified.

The varioustests used to illustrate the improved properties ofpthe filaments of this invention are described in detail inthe examples. A

' I '1. 1 1T XAMPL ly' affecting their unique properties.- In addition,;the cross A sample of polyester filaments'was prepared from a v copolymer of polyethylene tei'ephthala'te modified with 2 'mol' percent i sodium-2,5-di (carboniethoxy)benzene sulfontrte. The polymer had 7 a "relative viscosity of 22.3 as "measured in a 10% solution of the polymer in a mixture of 10 parts of phenol and 7 parts of 2,4,6-dichlorophenol polymer contained 0.3% titanium dioxide bywei ht' H The polymer was melt spun at 296- C. through a stain- 'less steel spinneret having 70 capillariesi Each spinneret orifice was triangular in shape with each side being 12 mils inlength The filaments, upon being extruded from the spinneregwere quenched in cross-flowing air having a velocity of65-fe'et'per minute ands temperature of 70 C. They were wound up as a 50-filament bimdle at a windup speed of 1500 yards per minute. The total denier of the spun yarn was 152. The spun yarn was then drawn at a temperature of 107 'C., using a one-quarter inch diameter snubbing pin, a draw ratio of 2.14, and a windup speed of 604 yards per minute. The drawn yarn was found to have a total denier of 70.3, a tenacity of 3 grams per denier, and a break elongation of 24.2%.

A taffeta fabric was woven from the'yarnf In weaving,

a twist of five Z turns per inch was used in the warp and zero twist in the filling. The loom. construction Was 100 -ends 80 picks. After weaving, the fabric was scoured at f the boil in an aqueous medium in a relaxed condition and '7 then dried. The fabric was then beat set for one minute at 390 F. and then finished. The fabric sample is identified as sample F-l. J For comparative purposes, similar fabrics were prepared from two other polyester yarns, each diflering from sample F-l only with respect to the cross-sectional configuration of the fibers usedjn the fabric. Sample F+2 was woven from round filaments and sample F-3 was woven from filaments having a trilobal configuration with parameters described in Table 1. Each of the fabrics were tested for covering power, luster highlight, and soil -rcsistance in accordance the followingtests.

A. COVERING Pownn.

1.. Percent transmitted lighf a determining the percent transmitted light, It, which after soiling. Launder-Ometer, manufactured by the AtlasElectric Deis a measure of white light transmitted by a fabric within the range of 1% to 20% transmission, a photoeIectric cell, a light source, and a sample were arranged in a wooden box, the inside surface of which was painted a flat black. The amount of light transmitted through a circular area of each sample which was illuminated by diffused light was measured. A l00-watt frosted'incandescent lamp placed six inches from the sample was used to illuminate the sample. The sample was hung in, a vertical plane free from externally applied tension and was held against a two-inch diameter hole. A Weston photoelcctric cell, model 594RR, was placed in the beam of transmitted light, about eighteen inches from the sample, and a Simpson microammeter, model 29 (0-50 microampere range), was used to measure the output of the cell. The instrument was calibrated by adjusting a variable transformer which was connected between the instrument and a constant voltage transformer to'give a meter-reading of 36.6 milliamperes when a neutral filter having a transmission of approximately 12.5% is'substituted for the fabric sampler Light transmission in percent as recorded in .Tablel was calculated byedividing -the, average of four meter readings for four samples by three.

2. Percent reflected light l i This testwas performed-in accordance with the measurements as described in US. Patent 2,828,528.

' B; Sorrmo Tnsr I A l 1.1Dry soil Therelative soilability of the wovenfabricg wastested by tumbling inthe-presence of a standarddry soil-composed of the following materials 1: s Grams Humus 35 Cement: -15 Silica(60200 mesh) 15 Clay (Kamec kaolin) 15 Sodium chloride 5 Carbon black a V 1.5 Iron oxide 7 0.25

Palmitic acid w 7 1.6 Oleic acid 1.6

Coconut oil V w 3 Lanolin (anhydrous) e l Kerosene a 2 Lauryl alcohol 0.5

were reported. The soiling-washing sequence was repeated twice. The reflectance measurements are the percent ofjthe original reflectance, "i.e., reflectance before soiling, retained after the washing following the second soiling. v i

Soiling was carried out by placing two samplesin each of two jars of soil. The jars were tumbled with one hun- -dred 0.25 inch stainless steel balls for forty-five minutes at 70 F. The reflectance of each sample was measured The samples were then washed in a vices Company, for twenty minutes in 200 ml. of distilled water at 100 F. with 0.25% of a detergent, made and sold by Procter and Gamble under the trade name Tide," and fifty 0.25 inch stainless steel balls. After washing, the samples were rinsed in distilled water, air dried, and the reflectance again determined. Reflectance measurements were determined using a Photovolt reflectometer, model 610 (Photovolt Corporation).

' was calibrated using a white enamel working standard (catalog #6162; Photovolt Corporation) having 70-75 percentage reflectance with a green tri stimulus filter (catalog #6130, Photovolt Corporation). 7

The instrument 2. Oily soil The procedure used in testing for resistance to oily soil is essentially the same as that described above for testing the resistance to dry soiling, except the soiling composition used is changed. The standard oil soil is composed of the following materials:

The above materials are dispersed in 3200 m1. of carbon tetrachloride and the dispersion stirred well before using. The reflectance measurements reported in Table l are on the same basis as those described for the dry soil test.

C. LUSTER HIGHLIGHT Rxrnvo The luster highlight rating was determined by averaging the subjective ratings of six persons. Ratings were made on a scale from 1 to 5 with a rating of 1 representing no luster highlight and a rating of 5 representing a high luster highlight.

TABLE 1 Sample F-l F-2 F-3 (Round) Filament parameters:

Angle A G)... 56 1. 46

x 8 120 x 86 Weight (OZJYdfi)-.. 1. 99 1. 96 2. Covering Power:

1: (percent) 5.4 6.0 4.8 1, (percent) 75.8 65.5 78.6 Selling Test (Percent Original Reflectance Retained):

Dry Soil- 59. 0 52. 8 61. 6 Oily Soil 75.1 67. 9 76. 7 Luster Highligh Ba 4. 25 1.25 3.08

The results of the tests show superior covering power for fabric sample F-l which was prepared from the filaments of the present invention than for the round filament control sample F-2. Similarly, greater resistance to soiling was shown for sample F-l than for sample F-2. The luster highlight for sample F-l was much greater than for either the round sample F-2 or the trilobal sample F-3. It was also found that the trilobal sample F-3 exhibited an over-all surface sheen which was not apparent in sample F-l.

EXAMPLE II Continuous filaments of polyethylene terephthalate were melt spun at a temperature of about 285 C. from a spinneret containing ten orifices having the shape shown in Fig. 5 in which R was 0.020 inch, R was 0.015 inch, and R was 0.001 inch. The polymer contained 0.3% by Weight of titanium dioxide. The filaments were wound up in a bundle at a speed of 600 yards per minute and were subsequently drawn about 4.5 times their original length. After drawing, the filaments had a denier of about 15. The cross-sectional shape had the following parameters: Arm angle A=l00;

Tip radius '%=0.25

and modification ratio M=1.35.

5 A yarn having a total denier of about 900 was prepared by plying the filaments together. The yarn was then bulked as described in the copending application of Breen and Lauterbach, Serial No. 698,103, filed November 22, 1957. Three ends of the bulked yarn were then plied and 10 twisted to give a total denier of approximately 3500.

This yarn was then tufted into a loop pile carpet containing about 22 ounces of pile yarn per square yard of jute backing; A carpet of similar construction was prepared using round filaments.

In comparing the two carpet samples, a unique luster highlight was exhibited by the carpet prepared from the filaments of the present invention. The luster highlight was absent in the sample prepared from the round filaments. The resistance to soiling'of the sample prepared 2 from the fibers of the present invention was significantly better than that prepared from the round fibers.

EXAMPLE III A number of polymethyl methacrylate cylinders were 25 machined to give enlarged fiber models having crosssectional shapes defined by the parameters listed in Table 2. The'models were rated subjectively by four persons .for luster highlight with a rating of 1.0 representing no luster highlight and a rating of 7.5 representing a very high luster highlight. The data recorded in the table was the average of the four evaluations.

TABLE 2 Arm 7'1 Sample No. Arig le M Rating 1 (Round) V V 1. 0 80 0. 52 1. 19 5. 0

9o 0. 1 1. 5a a. o

Another group of models having parameters outside the range of those of the present invention were prepared. The parameters and ratings for these models are set forth in Table 3 which follows.

TABLE 3 Sample No. Rating polymers are the polyami es such as polyhexamethylene adipamide, polyhexamethylene sebacamide, polycaproamide, polyxylylene azelamide, polyoctamethylene oxalamide, polypyrrolidone, polymet-aphenylene isophthalamide; polymetaphenylene adipamide; copolyamides, .and irradiation grafted polyamides; the polyesters and copolyesters such as the condensation productsof ethylene glycol with terephthalicacid, ethylene glycol with a 98/2 mixture of tere'phthalic/S-(sodium ,sulfo) -is ophthalic acids, ethylene glycol with a 90/ 10 mixture of terephthalic' and -isophthalic acids, polyesters derived from 2,2-bis(4'-hydroxyphenyl) propane, and trans-p-hexahydroxylylene glycol wit-h terephthalicacid; acrylonitrile polymers and copolymers such as polyacrylonitrile, copolymers and terpolymers of acrylonitrileand vinyl pyridine, vinylidene chloride, vinyl chloride, or methyl acrylate; vinyl chloride polymers and copolymers, vin'ylidene chloride polymers and copolymers; polyurethanes,e.g., thosedescribed in French Patent 1,172,566,- polyesteramides, polyethylenes, polypropylenes, especially linear polypropylene, polycarbonates such as those derived from 2,2-bis(4-hydroxyphenyl) propane, fiuorinated ethylene polymers and copolymers such as polymers of tetrafluoroethylene hexafluoropropene, 'and monochlorotrifluoroethylene; composite filaments such as, for example,'a sheath .of polyi amide around a core of polyester as described in/the-application of Breen, Serial 'No. 621,443, filedNovember 9, 1956, now abandoned,- of which Serial No. 771,676, filed November 3, 1958, is a continuation-in-part, and two 'acrylonitrile polymers ditfering in ionizable'group'eontent now..abandoned, of which'SerialNo. 771,677, filed November 3, 1958, is a continuation-in-part; cellulose derivatives such as cellulose acetate, regenerated cellulose, and

' e e hefib sv and fi ame t ma b st mr d 9! uncrimped, drawn or undrawn, bulked or unbulked, and

twisted or untwisted'. Mixtures of the above fibers as well as blends containing a major proportion of the synthetic fibers of this invention with a minor 'proportiqnlgf natpral fibers or synthetic fibers of other cross sections may "be used to prepare fabrics. The filaments 'mayjbe spunjin the form of two, monofilament yarn, mutilfilament yarn,

rving, or the like, The filaments of this invention are particularly .useful in bulked form. Bulking may be convenientlyfachieved by a number of methods. For example, aparticularly desirable bulking process is described in thecopending application of Breen and Lauterbach, Serial No. 698,103, filed November,22, .1957. The novel filamentsof this invention are peculiarly adaptable to being processed "by the bulking process of the just mentioned application. The filaments of this invention may also be treated according to e rqssss fi i h r e et s application of Breen and Sussman, Serial Nb. 810,671, filed May 4, 1958, to provide desirable products.

Obviously slight variations in the configuration of the filaments of this invention may be present without impairing their desirable properties. Slight distortions may be introduced in the filament when it' is spun, or during the processing operations such as drawing, crimping, twisting, dyeing, bulking, and the like. Also, the filamentsma contain small amounts of conventional additives-such as dyes, pigments, titanium dioxide (up to about' 2 %'),and thelike.

The chief advantage of this invention is that it prospun. as a sheath and core as described inthe application a of Taylor, Serial No. 640,722, filed February 18, 1957;

. 8 vides fibers, filaments, yarns, and fabrics having a unique combination of improved aesthetics andpleas ing optical properties. 1 In particular, it is possible, employing the'fibers of the present invention, to prepare apparel fabrics having a combination of high resistance to wrinkling, good suppleness, flexibility and drapability, low soil pick-up, easy soil removal, high crush resistance, good light fastness, and good dye wash fastness. Fabrics possessing these improved properties may be achieved in addition to having a high degree of luster. It has not been possible using any prior art cross sections either round or non-round to produce apparel fabrics having this combination of improved properties.

3 The novel fibers and'filaments of this invention may .velvets, and the like. a

As many widely drfierent embodinients" of thisinvention may be made without departing from the spirit and scope ;thereof, it is to bejunderstood that this invention is not to "be limited to the specific embodiments thereof except as defined in the appended claims;

I claim:

' =l."A textilefilament prepared from a synthetic polymer, the cross section of said filament having three convex sides" and three substantially symmetrical tip portions, said cross section having a tip radius ratio R V V and an Aim angle A essentially within the range represented by the cross-hatched area on Figure .3. of the drawing, and a modification ratio M essentially within the range represented by by the cross-hatched area on Figure 4 of the drawing. V

2. The filament of claim -1 wherein said polymer is a polyester. 7 r i 3. The filament of cla m -1 wherein said polymer is polypropylene.

4. The filament of claim -1' wherein said polymer is a polyamide.

5. The filament of claim 1 in staple fiber form. 6. A textile yarn comprising the filaments of claim 1.

7. The yarn of claim 6 wherein said filaments are continuous filaments.

8. A textile fabric prepared from the filaments of claim 1.

References Cited in the file of this patent,

UNITED STATES PATENTS 414,090 Taylor Oct. 29, 1889 1,773,969 Dreyfus et a1. Aug. 26, 1930 2,041,798 Taylor May 26, 1936 2,373,392 Hickey Apr. 17, 1945 2,831,748

Finlayson et al. Apr. 22, 1958 Parent No, 2 939 202 UNITED STATES PATENT orrrcr CERTlFlCATE 0F CERECWN June L 1960 Marlin Ce Holland 1% is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8 line 26 for 'ffoor" read floor --g line 4 1 strike out by second occurrence; line 65 for "2 373 392 Hickey read em 2 373 892 Hickey e Signed and sealed this 25th day of April 19619 (SEAL) Arrest:

ERNEST WC. SWIDER DAVID L. LADD Arresting Ofiicer Commissioner of Patents 

